Printing-film.



I different moisture conditions.

Patented June 7, 1904.

PATENT OFFICE.

THOMAS S. FOX, OF BROOKLYN, NEW YORK.

PRINTING-FILM.

SPECIFICATION forming part of Letters Patent No. 761,668, dated. June 7, 1904.

Application filed May 27, 1903. Serial No. 158,970- (No model.)

To all whom it may concern:

Be it known that I, THOMAS S. Fox, a citizen of the United States, residing in Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Printing-Films, of which the following is a specification.

This invention relates to flexible printingfilms which are practically unaffected by the absence or presence of moisture, variations in the amount of which may arise from changes changes in the physical condition of such face with atmospheric changes. Thus, although the film may be applied to its intended purpose with satisfactory results under given conditions as respects the amount of moisture in the atmosphere, it is found that owing to the effect of moisture upon a film of this kind such results are difficult of attainment with When an increased amount of moisture hasaccess to the film, it is found that its tenseness alters (such films when in use being usually in a stretched condition) and the firmness of the printingface becomes less. l/Vhile the elasticity and springiness of the printing portions deteriorate, they do not so readily take up a greasy printing-ink, and the film is liable to crack in course of time, owing to the drying out of the glycerin used in the film-forming mixture.

vI have found that a printing-film whose printing-face is formed from a material in which pyroxylin or similar compound enters largely as a constituent is not thus susceptible to changes or variations in the amount of accessible moisture, but preserves its elasticity, firmness, and characteristic satisfactory printing qualities under varying conditions.

A printing-film embodying the present in Vention includes, therefore, one in which the printing-face of the film is presented "by the face of a film or pellicle compounded from pyroxylin or analogous material. In order to impart the requisite degree of flexibility to such film, (which if made from pyroxylin alone might not possess this quality in the proper degree,) I may mix with such substance a suitable oleaginous material. Oastor-oil has been found to give good results in practice.

Various ways may be employed for preparing the printing-face of the film for printing, and whether such preparation embodies dots, lines, stipples, or printing portions of other configurations on the printing-face I consider them as coming within the scope of my present invention, provided the printing-face be made from a material having pyroxylin or analogous substance as a base.

In the manufacture of the material from which the printing-face is made I have found a good composition to result by mixing the parts in the proportion substantially of onetwelfth of a pound of pyroxylin to one pound of amyl acetate, to a gallon of which mixture from two to eight ounces of castor-oil is added. This formula is only given, however, as an instance of one that is suitable, since the present invention is not confined to its use alone.

In practice I find a convenient method for forming, the face is that of molding the same by drying and hardening the film-forming compound while the same is in a suitable matrix or mold the bottom of which is formed with lines, 860. that are to appear on the printing-face of the film.

In the drawings which accompany the pres ent specification, Figure 1 is a face view of the film, illustrating the printing-face thereof. Fig. 2 is a cross-sectional view of the film, and Fig. 3 is a similar section illustrating a modified construction.

The film (designated by 2 in Figs. 1 and 2) is here shown mounted upon a frame 3, being held by such frame under a proper tension to enable it to be used in the manner well known to those skilled in the art for the purpose of printing, preparing, and finishing drawings,

printing-surfaces, copying-surfaces, &c., by

present invention, that the printing-surface of the film after being inked is laid upon the face to which the inked lines, stipples, &c., of the printing-face are to be transferred and this transference effected by a proper tool, the portion or portions of the object under the film to which no transfer is to be made being stopped out by gum or in any other manner, the former material if used being subsequently Washed ofi". It is obvious also that while the printing-face of the film is formed of the material hereinbefore referred to the film at its rear side may be backed up With one or more layers of other materials suitable for the purpose, yielding a composite or built-up film, which nevertheless is flexible and usable in the same manner as before. Thus such a composite construction may be adopted for decreasing the cost of such films, for while the printing portions are made of the Waterproof pyroxylin compound the body of the film (to impart to the latter sufiicient rigidity) may, for instance, be made of the cheaper gelatinous compound, which in turn may be backed by a rubbing-face of the same nature as the printing-face. Such a structure is indicated in Fig. 3, in Which 4 is the printing-face, as before, 5 an intermediate layer of gelatin material, and 6 a rubbing-surface of pyroxylin compound.

The film, Whether the same be a simple integral structure or built up of a plurality of layers, may then be stretched by suitable means and properly secured to the frame.

A printing-film such as has been described hereinbefore is highly flexible and is not changed in those physical properties which influence its satisfactory use for the purposes described by changes in percentage of atmospheric humidity, is transparent, compressible, highly elastic under all the various conditions met With in practice, and does not deteriorate or crack in course of time.

Having described my invention, I claim 1. As a new article of manufacture, a flexible transparent printing-film, the prepared printing-face of which is made from pyroxylin.

2. As a new article of manufacture, a flexible transparent printing-film the prepared printing-face of which is made from a mixture having pyroxylin as a constituent.

3. As a new article of manufacture, a molded flexible transparent printing-film the prepared printing-faee of which is molded from pyroxylin.

4. As a new article of manufacture, a molded flexible transparent printi11g-film the prepared printing-face of which is molded from a mixture having pyroxylin as a constituent.

5. As a new article of manufacture, a flexible transparent printing-film having a prepared printing-face molded from a pyroxylin compound, combined with a frame on which the film is mounted under tension.

6. As a new article of manufacture, ailexible transparent printing-film made up of a plurality of layers that constituting the prepared printing-face being made from a mixture having pyroxylin as a constituent.

7. As a new article'of manufacture, a flexible transparent printing-film made up of a prepared printing-face layer and a rear layer of pyroxylin mixture and an intermediate layer of gelatin material.

8. As a new article of manufacture, a flexible transparent printing-film having a prepared printing-face formed from a mixture containing pyroxylin and caster-oil.

9. As a new article of manufacture, an open frame to the side bars of which there is socured under tension a flexible trans mrent printing-film, the prepared printing-face of which is made from a mixture having pyroxylin as a constituent.

Signed at Nos. 9 to 15 Murray street, New York, N. Y., this 26th day of May, 1903.

THOMAS S. FOX.

lVitnesses:

FRED. J. Donn, JOHN O. Smrnn'r. 

